Valve Seat Inspection And Refacing - Sym PA12B Service Manual

Valve Seat Inspection and Refacing

Clean up all carbon deposits onto intake and
exhaust valves.
Apply with emery slightly onto valve contact
face. Grind valve seat with a rubber hose or
other manual grinding tool.
Remove the valves and check if the contact
face is even or not.
Caution
The valve can not be ground. If the valve
is burned, worn, or its contact face is
uneven, replace it.
If the valve contacts the valve seat
unevenly after grinding, replace it.
Check the contact condition of the valve seat.
If the valve seat is too wide, too narrow, or
worn, refinish it.
Service limit：Valve seat width:
Valve contact face width: 1.8 mm
Valve seat grinding
Please use the valve seat cutter and follow
the instruction to grind the valve seat.
To this chapter contents
1.6 mm
Service limit：1.5mm
7. Cylinder Head / Valve
Valve seat
width
Service limit：1.8mm
60∘
32∘
45∘
7-11